Wafer container with oval latch

ABSTRACT

A wafer container includes a container body, in which a plurality of slots being disposed for supporting a plurality of wafers and an opening being formed on one sidewall of which for importing and exporting the plurality of wafers, and a door is joined with the opening of the container body for protecting the plurality of wafers therein, wherein the characteristic of the wafer container lies in that: at least one latch component is disposed in the door, the latch component including an oval cam with a pair of V-shape notches and on the surface of oval cam being a groove, a pair of moving bars including respectively an engaging portion, and a guiding element located on the moving bars, the engaging portion being engaged in the groove for the pair of moving bars to be respectively engaged with the oval cam.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a Front Opening Unified Pod (FOUP),and more particularly, to a latch component deployed in the door ofFOUP.

2. Description of the Prior Art

The semiconductor wafers need to be transferred to different workstations to go through various processes in required equipments. Inorder to facilitate the transferring of wafers and to prevent thepollution of wafers from occurring during transferring process, a sealedcontainer is provided for the automatic transferring process. Referringto FIG. 1, which is a view of wafer container of the prior art. Thewafer container is a Front Opening Unified Pod (FOUP) which includes acontainer body 10 and a door 20. The container body 10 is disposed witha plurality of slots 11 for horizontally receiving a plurality of wafers(not shown in Figure), and an opening 12 is located on a sidewall of thecontainer body 10 for importing and exporting the wafers. The door 20further includes an outer surface 21 and an inner surface 22, whereinthe door 20 is joined with the opening 12 of the container body 10 viathe inner surface 22 to protect the plurality of wafers within thecontainer body 10. Furthermore, at least one latch hole 23 is disposedon the outer surface 21 of the door 20 for opening or closing the wafercontainer. According to the aforementioned, due to that the wafers arehorizontally placed in the container body 10, thus, a wafer restraintcomponent is needed in the FOUP to prevent the wafer from displacementor from movement toward the opening 12 of container body 10 to occurduring the wafer transferring process due to vibration.

Referring to FIG. 2, which is a view of the door of FOUP disclosed inU.S. Pat. No. 6,736,268. As shown in FIG. 2, the inner surface 22 ofdoor 20 is disposed with a recess 24, which extends from the top end 221of the inner surface 22 to the bottom end 222 and is located between thetwo latch components 230 (within the door). The wafer restraint moduleconsisting of two wafer restraints 100 set aside each other is furtherdisposed in the recess 24. Each wafer restraint 100 further includes aplurality of wafer contacts 110 for sustaining corresponding wafers toprevent the wafers from being displaced or moving toward the opening ofthe container body due to vibration during the transferring process.However, the aforementioned wafer restraint module is disposed in therecess 24 of the inner surface 22 of the door 20, and thus the wafersare merely attached to the inner surface 22 of the door 20 or partiallysettled down within the recess 24. As a result, the wafers cannot besecurely and fully settled into the recess 24 in order to effectivelyshorten the length between the front side and the back side of the FOUP.In addition, dust particles generated due to the friction between thewafer restraint module and the wafers can be easily accumulated in therecess 24. In the process of cleaning the accumulated dust particles, itis necessary to separate the wafer restraint module from the recess 24on the inner surface 22 of the door 20. Frequent separation andre-assembly of the wafer restraint module thus causes the waferrestraint module to slacken easily.

Furthermore, FIG. 3 is a view of latch component 230 in the door 20 of aFront Opening Unified Pod (FOUP) as described in U.S. Pat. No.5,711,427. The method for assembling door 20 and container body 10 ismainly to dispose movable bolts 231 on the two sides of door 20, i.e.between outer surface 21 and inner surface 22, and to dispose socketholes 13 (referring to FIG. 1) near the edge of opening of door 10 forcorresponding to the bolts 231. The objective of fixing door 20 in thecontainer body 10 can thus be achieved with the rotation of latch hole23 (referring to FIG. 1) disposed on the outer surface 21 of door 20that leads to the insertion of latch bolts 231 into socket holes 13,wherein the insertion and withdrawal of bolts 231 is controlled by therotation of latch hole 23 via a round-shaped cam 232.

And in the actual operation of semiconductor factory, the opening ofFOUP is mainly operated through a Wafer Load Port, which comprises atleast a latch key. The latch key of this Wafer Load Port is insertedinto the latch hole 23 on the outer surface 21 of the door of FOUP forrotating the round-shaped cam 232 and thus driving the movable latchbolts 231 to open or close the FOUP. In addition, according to the SEMIstandards, the size of latch key and the size of latch hole arestandardized. However, in a FOUP designed according to the requiredstandards, an arrestment error of 9.44 degrees will occur when thecorresponding latch key and latch hole are rotated. Therefore, when theFOUP is horizontally placed, if the error is more than 9.44 degrees, thelatch key is not able to rotate the latch hole to operate the cam andthus the door cannot be successfully opened.

In addition, other U.S. patents that describe latch component in door ofFOUP include U.S. Pat. Nos. 5,915,562, 5,957,292, 6,622,883, and6,902,063. In order to achieve air tightness when joining the door andthe container body, the movable bolts of latch component will shiftlongitudinally for fastening a springy air-tight component, which leadsto achievement of both objectives of closing FOUP and achieving airtightness. However, in prior latch patents, complex mechanic apparatusesare used, which not only result in higher failure rate but also generatetoo much mechanical friction in the operating process that polluteswafers. Moreover, the air tightness achieved by fastening springyair-tight component with shift of movable bolts cannot sustain for verylong time and is not effective enough.

Moreover, in conventional FOUP, some restraint components are disposedon the inner surface of door 20. Thus when the door 20 closes containerbody 10, the restraint components contact wafers and completely fix thewafers in order to prevent displacement of wafers in FOUP from happeningduring transferring procedure. And in order to avoid too forcefulcollision or friction between restraint components and wafers whencontacting, therefore, as shown in FIG. 4, a few U.S. patents disclosespringy component 86 that is disposed between cam 232 in latch component230 and door 20. In the process in which cam 232 rotates and drivesmovable bolts 231 to close FOUP, this springy component 86 can functionas damping for restraint component disposed on inner surface of door 20to contact wafers under mitigated and smooth condition, and thus theproblem of collision and friction can be solved. U.S. patents related tosuch design include U.S. Pat. Nos. 6,880,718, 7,168,587, and 7,182,203.However, when this way of laterally driving is employed, it is easy foran offsetting force to generate on the moving direction of movable bolts231, which causes failure of insertion of movable bolts into socketholes 13 of container body 10. Thus, container body 10 and door 20cannot be closed, and more problems in the production occur.

SUMMARY OF THE INVENTION

In the door component of front opening unified pod (FOUP) of prior art,the latch component is composed of complex mechanic apparatus, which notonly leads to higher failure rate but also generates too much mechanicfriction in the operating process that may lead to pollution of wafer.One primary objective of the present invention is thus to provide afront opening unified pod (FOUP) disposed with latch component with ovalcam so that the moving bars can move to and fro on only one planesurface and the structure of the latch component can also be simplified.

Another primary objective of the present invention is to provide a frontopening unified pod (FOUP) disposed with latch component with oval cam,wherein with the correspondence of engaging portions and grooves, themoving bars can be driven by the oval cam to move to and fro on only oneplane surface, the design of which reduces friction generated in themoving process of moving bars and also reduces pollution.

Still another primary objective of the present invention is to provide afront opening unified pod (FOUP) disposed with latch component with ovalcam, wherein with the mutual interference of the guiding elements andthe V-shaped notches, even if there is an error in the angle of latchkey, the latch key can still be correctly inserted into the latch holeand drive the oval cam and thus to compensate and eliminate thearrestment error generated between the latch key and the latch hole forthe door to be successfully opened.

Yet another primary objective of the present invention is to provide afront opening unified pod (FOUP) disposed with latch component with ovalcam, wherein with the mutual interference of the guiding element and thelong narrow spring, even if there is an error in the angle of latch key,the latch key can still be correctly inserted into the latch hole anddrive the oval cam and thus to compensate and eliminate the arrestmenterror generated between the latch key and the latch hole for the door tobe successfully opened.

And still another primary objective of the present invention is toprovide a front opening unified pod (FOUP) disposed with latch componentwith oval cam, wherein with the correspondence of fixing structure andfixing notches, the function of automatic fixing is provided when theoval cam rotates either horizontal or perpendicular.

And yet another primary objective of the present invention is to providea front opening unified pod (FOUP) disposed with latch component withoval cam, wherein with the correspondence of spring element and fixingnotches, the function of automatic fixing is provided when the oval camrotates either horizontal or perpendicular.

And still another primary objective of the present invention is toprovide a front opening unified pod (FOUP) disposed with latch componentwith oval cam, wherein the inner surface of the door is disposed withwafer restraint components for effectively fixing the wafers.

And yet another primary objective of the present invention is to providea front opening unified pod (FOUP) disposed with latch component withoval cam, wherein the arrester of the center of oval cam is made ofpolymer plastic material, and more particularly of highly wear-resistantmaterial such as PEEK, to reduce particles generated during theto-and-fro operation and thus reduce the pollution in the FOUP.

According to above objectives, the present invention provides a frontopening unified pod (FOUP), which includes a container body and a door.A plurality of slots are disposed in the container body for sustaining aplurality of wafers, and an opening is formed on one sidewall of thecontainer body for importing and exporting the plurality of wafers. Thedoor includes an outer surface and an inner surface; the door is joinedwith the opening of container body via its inner surface for protectingthe plurality of wafers in the container body. The characteristic offront opening unified pod (FOUP) is in that: a recess is disposed in theinner surface of the door and the recess is located between twoplatforms, each of which is disposed with a latch component thatincludes an oval cam and an arrester disposed in the center of the ovalcam. At least a pair of V-shaped notches are disposed on a surface ofthe oval cam, and on the surface of the oval cam are disposed with atleast a groove, a pair of moving bars respectively disposed with anengaging portion which is engaged in the groove for the pair of movingbars to be engaged with the oval cam, and a guiding element disposed onthe moving bars. Wherein the arrester is used to control the rotation ofthe oval cam for the moving bars to go to and fro between the pair ofsocket holes and the pair of latch holes.

The present invention then provides a front opening unified pod (FOUP),which includes a container body and a door. A plurality of slots aredisposed in the container body for sustaining a plurality of wafers, andan opening is formed on one sidewall of the container body for importingand exporting the plurality of wafers. The door includes an outersurface and an inner surface; the door is joined with the opening ofcontainer body via its inner surface for protecting the plurality ofwafers in the container body. The characteristic of front openingunified pod (FOUP) is in that: a recess is disposed in the inner surfaceof the door and the recess is located between two platforms, each ofwhich is disposed with a latch component that includes an oval cam andan arrester disposed in the center of the oval cam. A plurality ofV-shaped notches are disposed on the two opposite ends of the longer andthe shorter diameters of the oval cam, and on a surface of the oval camare disposed with at least a groove, a pair of moving bars respectivelydisposed with an engaging portion which is engaged in the groove for thepair of moving bars to be engaged with the oval cam, and a guidingelement disposed close to the end where the moving bars and the oval camare engaged with each other. The guiding element is composed of aguiding wheel and at least a pair of guiding rods disposed on theguiding wheel. Wherein the arrester is used to control the rotation ofthe oval cam for the moving bars to go to and fro between the pair ofsocket holes and the pair of latch holes.

The present invention further provides a front opening unified pod(FOUP), which includes a container body and a door. A plurality of slotsare disposed in the container body for sustaining a plurality of wafers,and an opening is formed on one sidewall of the container body forimporting and exporting the plurality of wafers. The door includes anouter surface and an inner surface; the door is joined with the openingof container body via its inner surface for protecting the plurality ofwafers in the container body. The characteristic of front openingunified pod (FOUP) is in that: a recess is disposed in the inner surfaceof the door and the recess is located between two platforms, each ofwhich is disposed with a latch component that includes an oval cam andan arrester disposed in the center of the oval cam of the latchcomponent. A surface of the oval cam is disposed with at least a groove,a pair of moving bars respectively disposed with an engaging portionwhich is engaged in the groove for the pair of moving bars to be engagedwith the oval cam, a guiding element disposed at the center of the ovalcam, and a long narrow spring framingly disposed on the guiding element.Wherein the arrester is used to control the rotation of the oval cam forthe moving bars to go to and fro between the pair of socket holes andthe pair of latch holes.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a view of the front opening unified pod (FOUP) of the priorart;

FIG. 2 is a view of the door of the front opening unified pod (FOUP) ofthe prior art;

FIG. 3 is a view of another door of front opening unified pod (FOUP) ofthe prior art;

FIG. 4 is a view of still another door of front opening unified pod(FOUP) of the prior art;

FIG. 5A is a view of the door of a front opening unified pod (FOUP) ofthe present invention;

FIG. 5B is a view of the latch component of the present invention;

FIG. 5C is a stereogram of the oval cam of the present invention;

FIG. 6A to FIG. 6E are views of the operation of latch component of thepresent invention;

FIG. 7A is a view of the door of a front opening unified pod (FOUP) ofthe present invention;

FIG. 7B is a front view of the latch component of the present invention;

FIG. 7C is a rear view of the latch component of the present invention;

FIG. 8A to FIG. 8E are views of the operation of latch component of thepresent invention;

FIG. 9A is a view of the door of a front opening unified pod (FOUP) ofthe present invention;

FIG. 9B is a view of the latch component of the present invention;

FIG. 10A to FIG. 10C are views of the operation of latch component ofthe present invention;

FIG. 11 is a view of a front opening unified pod (FOUP) of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention discloses a front opening unified pod (FOUP),which includes a container body and a door. A plurality of slots aredisposed in the container body for sustaining a plurality of wafers, andan opening is formed on one sidewall of the container body for importingand exporting the plurality of wafers. The door includes an outersurface and an inner surface; the door is joined with the opening ofcontainer body via its inner surface for protecting the plurality ofwafers in the container body. Moreover, the outer surface of the door isdisposed with at least a latch hole for opening or closing the FOUP. Thestructure of FOUP utilized in the present invention is the same as thatof FOUP as described above, and therefore the details of manufacturingor processing processes are not completely described in the following.The drawings referred to in the following description are not madeaccording to actual sizes and their function is only to illustratecharacteristics of the present invention. In addition, the technicalcontents and objectives of and the effects achieved by the presentinvention are all completely and detailedly disclosed in the followingdescription accompanied by drawings and signs.

First of all, the basic structure of FOUP (referring to FIG. 2)comprises a door 20 with its inner surface 22 disposed with a recess 24that is located between two platforms 25, each platform 25 beingdisposed with a latch component 230. Then referring to FIG. 5A, which isa top view of the first embodiment of latch component of the presentinvention. As shown in FIG. 5B, each latch component 30 is composed ofan oval cam 31 with a pair of V-shaped notches 311, a pair of movingbars 32 respectively disposed with an engaging portion 321, a guidingelement 322 disposed on the pair of moving bars 32, and a fixing spring33 that is integrated with the moving bars 32, wherein the guidingelement 322 is on one end of the moving bars 32 and is roughly U-shaped.Moreover, the surface of the oval cam 31 is disposed with at least agroove 312, in which the pair of engaging portions 321 of the movingbars 32 are respectively engaged for the pair of moving bars 32 to beengaged with the oval cam 31. Referring then to FIG. 5C, at least a pairof fixing notches 313 are oppositely disposed on the two ends of thelong-axis diameter and the short-axis diameter of the oval cam 31, andan oval platform 314 is protrusively disposed on the surface of the ovalcam 31 disposed with groove 312, the square measure of the oval platform314 being smaller than that of the oval cam 31 and the V-shaped notches311 on the oval cam 31 being disposed on the two ends of the longerdiameter of the oval platform 314.

In the first embodiment of the present invention, the oval cam 31 can bemade of metal (such as stainless steel) or polymer plastic material(such as Teflon and PEEK), which is not limited in the presentinvention. As shown in FIG. 5B, an arrester 315 is further disposed atthe center of the oval cam 31. When the opening latch (not shown inFigure) of the Wafer Load Port is inserted into the latch hole 23 of thedoor 20, it connects the arrester 315 to drive the oval cam 31 torotate. Since the arrester 315 and the opening latch are in contact witheach other in the process in which the oval cam 31 is driven to rotate,the arrester 315 of the present invention can be made of polymer plasticmaterial, especially highly wear-resistant material such as PEEK, toreduce particles generated during the to-and-fro operation and pollutionin the FOUP.

Then, referring to FIGS. 6A to 6E, which are views of the rotationprocess of oval cam of the first embodiment of the present invention. Inthe present embodiment, by controlling the rotation of the oval cam 31,the moving bars 32 go to and fro between a pair of socket holes 13 (asshown in FIG. 1) and a pair of latch holes 26 (as shown in FIG. 2). Theway of operation is as sequentially shown in FIGS. 6A to 6E, in whichthe rotation process of oval cam is viewed as being rotated clockwisefor 90 degrees. The long-axis distance of the oval cam is used forpushing the moving bars 32 out of the latch holes 26 for the moving bars32 to be inserted into the socket holes 13. And vice versa, if therotation process of oval cam is sequentially shown in FIGS. 6E to 6A,then the process is viewed as being rotated counter-clockwise for 90degrees, wherein the moving bars 32 are pulled out of the socket holes13 and withdrawn into the latch holes 26. The mechanical principle isthat, with the oval cam 31 having a longer diameter X and a shorterdiameter Y (as shown in FIG. 5A), the moving bars 32 will operateaccording to the changing radius of the oval cam 31 when the oval cam 31rotates. Moreover, what is to be emphasized is that, the aforementionedway of rotation of the oval cam 31 can also lead the guiding elements322 of moving bars 32 and the V-shaped notches 311 of oval cam 31 tointerfere with each other so that the oval cam 31 automatically rotatesto a fixed position when rotating to a certain angle for the moving bars32 to be pushed out of or withdrawn into the latch holes 26.

The way how the guiding elements 322 and the V-shaped notches 311 of thepresent embodiment interfere with each other is further described: whenthe rotation position of oval cam 31 is as shown in FIG. 6A, i.e. a pairof the fixing portion 325 of the fixing structure 323 of the moving bars32 are in contact with the fixing notch 313 of the two ends of theshorter diameter Y of the oval cam 31, the guiding elements 322 and theoval platform 314 merely contact with and resist each other; when therotation position of oval cam 31 is as shown in FIG. 6B, the moving bars32 extend toward the exterior since the radius of the oval cam 31becomes longer, and the fixing spring 33 is also pulled by the movingbars 32 and receives a pressure since the moving bars 32 and the fixingspring 33 are integrated with each other; when the rotation position ofoval cam 31 is as shown in FIG. 6C (the difference between the rotationposition shown in FIG. 6A and that in FIG. 6C is 68 degrees), theguiding elements 322 are in contact with and resist a vertex of V-shapednotches 311 of the oval cam 31, and at the same time, the pressurereceived by the fixing spring 33 is larger than that received as in FIG.6B; when the rotation position of oval cam 31 is as shown in FIG. 6D,i.e. the oval cam 31 rotates more than 68 degrees, the point where theguiding elements 322 and the V-shaped notches 311 contact and resisteach other is beyond the vertex, and thus the pressure received by thefixing spring 33 is smaller than that received as in FIG. 6C; as thepressure received by the fixing spring 33 is released, the oval cam 31rotates automatically to FIG. 6E, and the guiding elements 322 slidein-between the two vertexes of the V-shaped notches 311 and halt.Following the operation described above, the moving bars 32 are nowpushed out of the latch holes 26 and inserted into the socket holes 13of the container body 10 for the door 20 to lock and close the containerbody 10. In the present embodiment, when the FOUP of the presentinvention is horizontally placed, even if the error in angle of theopening latch (not shown in Figure) of the Wafer Load Port is largerthan 9.44 degrees, the oval cam 31 can still be operated to compensateand eliminate the arrestment error between the opening latch and thelatch holes 23 for the door to be successfully locked or opened.Similarly, for the door 20 to be detached from the container body 10,the rotation position of oval cam 31 changes from that shown in FIG. 6Eto that shown in FIG. 6C with the oval cam 31 rotating 22 degreescounter-clockwise; when the rotation degree is larger than 22 degrees,the guiding elements 322 move away from the V-shaped notches 311 and theoperation of opening is completed.

The operation of oval cam 31 is described in detail as above. Referringthen to FIG. 5B, a fixing structure 323 is further disposed near the endwhere the moving bars 32 and the oval cam 31 are engaged with each otherin the present invention. The fixing structure 323 is a hollowed-outspring element 324 and has a fixing portion 325 protruding from thespring element 324; the fixing structure 323 is integrated with themoving bars 32 and is manufactured by injection molding. When the ovalcam 31 automatically rotates to a fixed position, i.e. the oval cam 31rotates to a horizontal fixed position as shown in FIG. 6A or to aperpendicular fixed position as shown in FIG. 6E, the fixing portion 325on fixing structure 323 and the fixing notch 313 snap with and fix eachother to provide the function of automatic aligning-fixing and halting.

Referring to FIG. 7A, which is a top view of the second embodiment oflatch component of the present invention. FIG. 7B is a front view of thelatch component, and FIG. 7C is a rear view of the latch component. Asshown in FIG. 7B, each latch component 40 is composed of an oval cam 41with four circumferential vertexes respectively having a pair ofV-shaped notches 411, a pair of moving bars 42 respectively having anengaging portion 421 (as shown in FIG. 7C), and a guiding element 422disposed on the moving bars 42. Then referring to FIG. 7C, at least agroove 412 is disposed on the surface of oval cam 41 for the engagingportions 421 of the pair of moving bars 42 to be respectively engaged inthe groove 412, and thus the pair of moving bars 42 can be engaged withthe oval cam 41. Furthermore, the structure of V-shaped notches 411 onthe two opposite ends of the long and the short diameters of the ovalcam 41 is shown in FIG. 7B, the V-shape notches 411 being formed by alonger side 41L and a shorter side 41S. In addition, the guiding element422 is disposed near the end where the moving bars 42 and the oval cam41 engage with each other. The guiding element 422 is composed of aguiding wheel 423 and a pair of guiding rods 424 that are disposed onthe guiding wheel 423, the pair of guiding rods 424 protruding from theedge of the guiding wheel 423 and being neighboring to each other. Inaddition, a pair of fixing notches 426 can be further disposed on theguiding wheel 423 between the two guiding rods 424.

In the present embodiment, the oval cam 41 can be made of metal (such asstainless steel) or polymer plastic material (such as Teflon and PEEK),which is not limited in the present invention. As shown in FIG. 7B, anarrester 415 is further disposed at the center of the oval cam 41. Whenthe opening latch of the Wafer Load Port is inserted into the latch hole23 of the door 20, it connects the arrester 415. Since the opening latchand the arrester 415 are in contact with each other in the process inwhich the oval cam 41 is driven to rotate, therefore, to reduce frictionbetween the opening latch and the arrester 415, the arrester 415 of thepresent invention can be made of polymer plastic material, especiallyhighly wear-resistant material such as PEEK, to reduce particlesgenerated during the to-and-fro operation and pollution in the FOUP.

Then, referring to FIGS. 8A to 8E, which are views of the rotationprocess of oval cam of the second embodiment of the present invention.In the present embodiment, by controlling the rotation of the oval cam41, the moving bars 42 go to and fro between a pair of socket holes 13(as shown in FIG. 1) and a pair of latch holes 26 (as shown in FIG. 2).First, when the socket holes 13 on the moving bars 42 and the latchholes 26 are to be joined with each other, i.e. when the door 20 of theFOUP is to be closed, the way of operation is as sequentially shown inFIGS. 8A to 8C, in which the rotation process of oval cam 41 is viewedas being rotated counter-clockwise for 90 degrees, the moving bars 42being pushed out of the latch holes 26 and inserted into the socketholes 13; when the socket holes 13 on the moving bars 42 are to bedetached from the latch holes 26, i.e. when the door 20 of the FOUP isto be opened, the way of operation is as sequentially shown in FIGS. 8Cto 8E, in which the rotation process of oval cam 41 is viewed as beingrotated clockwise for 90 degrees, the moving bars 42 being pulled out ofthe socket holes 13 and withdrawn into the latch holes 26. Themechanical principle of what is described above is that, with the ovalcam 41 having a longer diameter X and a shorter diameter Y (as shown inFIG. 7A), the moving bars 42 will operate according to the changingradius of the oval cam 41 when the oval cam 41 rotates. Moreover, therotation of the oval cam 41 can also lead the guiding elements 422 ofmoving bars 42 and the V-shaped notches 411 of oval cam 41 to interferewith each other so that the oval cam 41 automatically rotates to a fixedposition when rotating to a certain angle for the moving bars 42 to bepushed out of or withdrawn into the latch holes 26.

The way how the guiding elements 422 and the V-shaped notches 411 of thepresent embodiment interfere with each other is further described: whenthe rotation position of oval cam 41 is as shown in FIG. 8A, i.e. theguiding rods 424 are snapped with the shorter side 41S of the V-shapednotch 411; when the oval cam 41 is driven by the opening latch to rotatecounter-clockwise, namely, the different between the rotation positionas shown in FIG. 8A and that in FIG. 8C is about 68 degrees, the longerside 41L of the V-shaped notch 411 pushes the guiding rods 424 to drivethe guiding wheel 423 to rotate, and the moving bars 42 protrude towardthe exterior because the radius of the oval cam 41 becomes longer; whenthe rotation position of oval cam 41 is as shown in FIG. 8B, an end ofthe V-shaped notch 411 is located between the pair of guiding rods 424and is in contact with and resists the guiding rods 424; when the ovalcam 41 continues to rotate counter-clockwise, i.e. the degree it rotatesis larger than 68 degrees, the guiding rods 424 automatically slide intothe V-shaped notch 411 along the longer side 41L of the V-shaped notch411 and make the guiding element 422 halt for a guiding rod 424 tocontact and resist the shorter side 41S of the V-shaped notch 411,meantime the oval cam 41 rotating counter-clockwise for about 90degrees, as shown in FIG. 8C. Following the operation described above,the moving bars 42 are now pushed out of the latch holes 26 and insertedinto the socket holes 13 for the door 20 to lock and close the containerbody 10. In the present embodiment, when the FOUP of the presentinvention is horizontally placed, even if the error in angle of theopening latch (not shown in Figure) of the Wafer Load Port is largerthan 9.44 degrees, the oval cam 41 can still be operated to compensateand eliminate the arrestment error between the opening latch and thelatch holes 23 for the door to be successfully locked or opened. Then,for the door 20 to be detached from the container body 10, the rotationposition of oval cam 41 changes from that shown in FIG. 8C to that shownin FIG. 8D with the oval cam 41 rotating 68 degrees clockwise; when therotation degree is larger than 68 degrees, the guiding rods 424 moveaway from the V-shaped notches 411 and the operation of opening the door20 is completed.

In addition to the operation of oval cam 41 as described above, thepresent invention further discloses another embodiment in which themoving bars 42 are further disposed with a spring element 425. Referringthen to FIG. 7B, the two ends of the spring element 425 extend from thetwo sides of the hollowed-out structure of moving bars 42 to the centerand together form a third end and a T-shaped structure is thus formed.Therefore the spring element 425 is integrated with the moving bars 42and is manufactured by injection molding. Moreover, the third end isthen embedded in a fixing notch 426 on the guiding wheel 423. When theoval cam 41 automatically rotates to a fixed position, i.e. the oval cam41 rotates to a horizontal fixed position as shown in FIG. 8A or to aperpendicular fixed position as shown in FIG. 8C, the third end ofT-shaped structure of spring element 425 respectively snaps with andfixes a pair of fixing notches 426 to provide the function of automaticaligning-fixing and halting.

Then, referring to FIG. 9A, which is a top view of the third embodimentof latch component 50 of the present invention. As shown in FIG. 9B,each latch component 50 is composed of an oval cam 51, a pair of movingbars 52 respectively having an engaging portion 521, a guiding element53 disposed at the center of oval cam 51, and a long narrow spring 54framingly disposed on the guiding element 53, wherein the long narrowspring 54 can be made of elastic materials such as polymer plasticmaterial and rubber material, which is not limited in the presentinvention.

In the present embodiment, at least a groove 512 is disposed on thesurface of the oval cam 51 for the engaging portions 521 of the pair ofmoving bars 52 to be respectively engaged in the groove 512 so that themoving bars 52 can be engaged with the oval cam 51. Moreover, theguiding element 53 of the present embodiment is composed of arectangular flange 531 with a rounded inner groove 532 formed in itsinner side, a pair of rollers 533, and an bearing 534, wherein oppositecorners of the inner side of the rectangular flange 531 are respectivelydisposed with a through hole 535 that penetrates the inner and outersides of the rectangular flange 531 for a roller 533 to be respectivelydisposed in each through hole 535. A hollow cylinder 536 is furtherdisposed at the center of the rounded inner groove 532. The oval cam 51,the rectangular flange 531, and the hollow cylinder 536 are integratedas one piece. Moreover, a bearing 534 is circumferentially disposed onthe hollow cylinder 536, and the rim of the bearing 534 has a ring 534 awith a notch, in which are a plurality of balls 534 b. By using thebearing 534 in the present embodiment, not only can the rotation of theoval cam 51 become smoother, but the particles generated due to frictioncan also be reduced and the pollution in FOUP can also be prevented.

The operation of the present embodiment is then described in detail.First, the oval cam 51 in the present embodiment can be made of metal(such as stainless steel) or polymer plastic material (such as Teflonand PEEK), which is limited in the present invention. Then, referring toFIG. 9B, an arrester 513 is further disposed at the center of the ovalcam 51. The arrester 513 is a rectangular structure with its long axishorizontally deployed along with the diameter X of the oval cam 51 (asshown in FIG. 9A). The guiding element 53 is further disposed on thearrester 513, the pair of corners of which without disposing rollers 533respectively overlap and connect with the two shorter sides of thearrester 513. When the opening latch of the Wafer Load Port is insertedinto the latch hole 23 of the door 20, it connects the arrester 513.Since the opening latch and the arrester 513 are in contact with eachother in the process in which the oval cam 51 is driven to rotate,therefore, the arrester 513 of the present invention can be made ofpolymer plastic material, especially highly wear-resistant material suchas PEEK, to reduce particles generated during the to-and-fro operationand pollution in the FOUP.

Then, referring to FIGS. 10A to 10C, which are views of the rotationprocess of oval cam of the third embodiment of the present invention. Inthe present embodiment, by controlling the rotation of the oval cam 51,the moving bars 52 go to and fro between a pair of socket holes 13 (asshown in FIG. 1) and a pair of latch holes 26 (as shown in FIG. 2).First, when the socket holes 13 on the moving bars 52 and the latchholes 26 are to be joined with each other, i.e. when the door 20 of theFOUP is to be closed, the way of operation is as sequentially shown inFIGS. 10A to 10C, in which the rotation process of oval cam 51 is viewedas being rotated clockwise for 90 degrees, the moving bars 52 beingpushed out of the latch holes 26 and inserted into the socket holes 13;when the socket holes 13 on the moving bars 52 are to be detached fromthe latch holes 26, i.e. when the door 20 of the FOUP is to be opened,the way of operation is as sequentially shown in FIGS. 10C to 10A, inwhich the rotation process of oval cam 51 is viewed as being rotatedcounter-clockwise for 90 degrees, the moving bars 52 being pulled out ofthe socket holes 13 and withdrawn into the latch holes 26. Themechanical principle of what is described above is that, with the ovalcam 51 having a longer diameter X and a shorter diameter Y (as shown inFIG. 9A), the moving bars 52 will operate according to the changingradius of the oval cam 51 when the oval cam 51 rotates. Moreover, therotation of the oval cam 51 can also lead one end of the moving bars 52,the guiding elements 53 of oval cam 51, and the long narrow spring 54 tointerfere among one another so that the oval cam 51 automaticallyrotates to a fixed position when rotating to a certain angle for themoving bars 52 to be pushed out of or withdrawn into the latch holes 26.

The way how one end of the moving bars 52, the guiding elements 53 ofoval cam 51, and the long narrow spring 54 as described above interfereamong one another is further described: when the rotation position ofoval cam 51 is as shown in FIG. 10A, the moving bars 52 and the longnarrow spring 54 contact and resist each other, and the inner edge ofthe long narrow spring 54 is neighboring to and contacts one side of therectangular flange 531 of the guiding element 53; therefore, the widthof the opening of the long narrow spring 54 framingly disposed on theguiding element 53 is equivalent to the width of the rectangular flange531. When the oval cam 51 rotates clockwise (the difference between therotation position as shown in FIG. 10A and that in FIG. 10B is about 45degrees), the way in which the long narrow spring 54 contacts therectangular flange 531 changes from contacting on neighboring sides tocontacting via rollers 533. The rollers 533 also roll along the inneredge of the long narrow spring 54, and meantime the width of the openingof the long narrow spring 54 is equivalent to the length of the diagonalline of the rectangular flange 531. When the oval cam 51 continues torotate clockwise (meaning the rotation degree is larger than 45degrees), the size of opening of the long narrow spring 54 decreases asthe rectangular flange 531 rotates. Meantime, a restoring force isgenerated by the long narrow spring 54 so that the rollers 533 arepressed and roll automatically to one side of the rectangular flange 531till they are neighboring to and in contact with the inner edge of thelong narrow spring 54, as shown in FIG. 10C, meantime the width of theopening of the long narrow spring 54 framingly disposed on the guidingelement 53 being equivalent to the width of the rectangular flange 531.Following the operation described above, the moving bars 52 are nowpushed out of the latch holes 26 and inserted into the socket holes 13for the door 20 to lock and close the container body 10. In the presentembodiment, when the FOUP of the present invention is horizontallyplaced, even if the error in angle of the opening latch (not shown inFigure) of the Wafer Load Port is larger than 9.44 degrees, the oval cam51 can still be operated to compensate and eliminate the arrestmenterror between the opening latch and the latch holes 23 for the door tobe successfully locked or opened. Then, for the door 20 to be detachedfrom the container body 10, the rotation position of oval cam 51 changesfrom that shown in FIG. 10C to that shown in FIG. 10B with the oval cam41 rotating 45 degrees counter-clockwise; when the rotation degree islarger than 45 degrees, the rotation of the rectangular flange 531results in change in the width of the opening of the long narrow spring54 and a restoring force is generated by the long narrow spring 54 todrive the rollers 533 to roll, and thus the operation of opening iscompleted. Moreover, with the rollers 533 and the long narrow spring 54corresponding to each other, the particles generated due to friction canbe greatly reduced and the pollution in FOUP can be prevented.

Then, referring to FIG. 11, which is a view of wafer container of thepresent invention. The wafer container is a front opening unified pod(FOUP), which includes a container body 10 and a door 20. A plurality ofslots 11 are disposed in the container body 10 for sustaining aplurality of wafers, and an opening 12 is formed on one sidewall of thecontainer body 10 for importing and exporting the plurality of wafers.The door 20 includes an outer surface 21 and an inner surface 22. Theouter surface 21 of the door 20 is disposed with at least a latch hole(not shown in Figure) for opening or closing the FOUP, and the center ofinner surface 22 of the door 20 is disposed with a recess 24 that islocated between two platforms 25, wherein the aforementioned latchcomponent 60 is disposed in the two platforms 25. The primary objectiveof the recess 24 is to sustain the plurality of wafers in the containerbody 10 for shortening the length between the front side and the backside of the FOUP. A wafer restraint module 60 is respectively disposedon two platforms 25 for restricting the movement of wafers toward theopening of the wafer container and controlling the number of waferssettling down the recess 24.

The length of the recess 24 of the inner surface 22 of door 20 asdescribed above is related to the distance between slots 11 in containerbody 10 and the number of the wafers. The distance between 12″ wafershas been a standard regulation in the industry to achieve maximumcapacity of loading and ensure at the same time that there is enoughspace for the mechanical arm to stretch in for importing or exportingwafers. In general, the number of wafers to be in the wafer container is25 pieces. However, the width and the depth of recess 24 of the presentinvention can be adjusted. When the thickness of the door 20 isconstant, the depth of recess 24 can be adjusted to be deeper for thewhole wafer to be placed further into recess 24, and the width of recess24 can also be adjusted to be wider accordingly.

Furthermore, the inner surface 22 of door 20 of the present inventioncan be a plane surface or can be without recess; at least a latchcomponent (such as the aforementioned component 30, 40, 50) can bedisposed between the inner surface 22 and the outer surface 21, and alatch component is disposed in one preferred embodiment. The latchcomponent 30, 40, or 50 is the same as what is described in theaforementioned embodiment and will not be described in detail. Inaddition, in order for the plurality of wafers already placed in thecontainer body 10 to be fixed when the door 20 closes the container body10, at least a restraint module 60 can be disposed on the inner surface22 of the above-mentioned plane surface or at least a restraint modulecan be disposed near the central area of the above-mentioned planesurface, as shown in FIG. 11.

Obviously, the latch component of the present invention can only maketo-and-fro movement when being driven by the oval cam, moving forwardand backward, and no shift will occur on the longitudinal (vertical)direction. Therefore, the latch component of the present invention is asimpler design. When the door and the container body of the presentinvention close, a pair of moving bars are driven by the oval cam tomove toward the edge of the door, and the front plane of moving barsthen go through latch holes on the door and are fastened in socket holescorresponding to latch holes near the edge of the opening of containerbody. Then, an aeration device can be disposed for aerating air-tightcomponent (not shown in Figure) between the door and the container bodyto isolate interior from exterior of container body.

While the invention has been described by way of examples and in termsof the preferred embodiments, it is to be understood that the inventionis not limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements aswould be apparent to those skilled in the art. Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

1. A wafer container including a container body having a plurality ofslots therein for receiving a plurality of wafers and having an openingformed on one sidewall of which for importing or exporting saidplurality of wafers, at least a pair of socket holes being disposed atan edge of said opening of said container body; and a door having anouter surface and an inner surface with at least a pair of latch holescorresponding to said pair of socket holes being disposed at the edge ofsaid door, said door joining with said opening of said container bodyvia said inner surface for protecting said plurality of wafers in saidcontainer body, the characteristic of said wafer container in that: arecess is disposed on said inner surface of said door and locatedbetween two platforms, and each said platform is disposed with a latchcomponent, said latch component comprising an oval cam with an arresterdisposed at its center, at least a pair of V-shaped notches disposed onone surface of said oval cam, said surface of said oval cam beingdisposed with at least a groove, an oval platform disposed on saidsurface of said oval cam, in which said pair of V-shaped notches of saidoval cam are disposed on two ends of longer diameter of said ovalplatform, a pair of moving bars respectively having an engaging portionthat are engaged in said groove for said moving bars to be engaged withsaid oval cam, and a guiding element disposed on said moving bars,wherein said arrester is used to control the rotation of said oval camfor said moving bars to go to and fro between said pair of socket holesand said pair of latch holes.
 2. The wafer container according to claim1, wherein at least a pair of fixing notches are further oppositelydisposed on two ends of diameter of said oval cam.
 3. The wafercontainer according to claim 2, wherein a fixing structure is furtherdisposed on said moving bars and said fixing structure comprises ahollowed-out spring element and a fixing portion.
 4. The wafer containeraccording to claim 1, further comprising a pair of fixing spring whichare integrated with said moving bars.
 5. The wafer container accordingto claim 1, wherein material of said oval cam and of said arrester isselected from the group consisting of: metal material or polymer plasticmaterial.
 6. The wafer container according to claim 1, wherein at leasta restraint module is further respectively disposed on said twoplatforms.